Hydraulically operated machines, such as, wheel loaders, excavators mining shovels etc. are typically employed to move heavy loads, such as construction material, debris and/or any other material. These machines utilize an implement system to carry the load. The implement system is generally powered by one or more hydraulic actuators which are fluidly coupled to an engine driven pump. The pump selectively supplies pressurized fluid into the chambers of the hydraulic actuators. As the pressurized fluid moves into or through the chambers, the pressure of the fluid acts on hydraulic surfaces of pistons within the chambers of the hydraulic actuators, to affect movement of the hydraulic actuators and thus a movement of the implement system is achieved.
During operation of such machine, the implement system may be raised to an elevated position, and lowered. As the implement system is relatively heavy and also carry load, the implement gains potential energy when raised to the elevated position. Typically, as the implement is lowered from the elevated position, this potential energy may be converted to heat as the pressurized hydraulic fluid is forced out of the hydraulic actuator and is throttled across a valve and returned to a tank. The conversion of potential energy into heat may result in an undesired heating of the hydraulic fluid, which may require the machine to have an additional cooling mechanism and added capacity.
U.S. Publication No. 2013/0318955 (Hereinafter referred to as '955 Publication). The '955 Publication discloses a hydraulic system having a hydraulic actuator, a pump configured to supply fluid to the hydraulic actuator, and a first accumulator fluidly coupled to the hydraulic actuator. The first accumulator is configured to store fluid received from the hydraulic actuator. The hydraulic system also includes a motor drivingly connected to the pump and fluidly coupled to the first accumulator. The motor is configured to receive the stored fluid from the first accumulator to drive the pump. The hydraulic system further includes a first discharge valve fluidly coupled between the first accumulator and the hydraulic actuator. The first discharge valve is configured to supply the stored fluid from the first accumulator to the hydraulic actuator without the stored fluid from the first accumulator circulating through the pump.